## Tuesday, 28 February 2017

### TARGET SBI PO DAY1:Mixtures And Alligations

1.A vessel is filled with liquid, 4 parts of which are water and 5 parts syrup. How much of the mixture must be drawn off and replaced with water so that the mixture may be half water and half syrup?
A.1/9
B.1/10
C.1/5
D.1/12
E.1/7

2.Rice worth Rs. 126 per kg and Rs. 134 per kg are mixed with a third variety in the ratio 1 : 1 : 2. If the mixture is worth Rs. 177 per kg, the price of the third variety per kg will be:
A.254
B.216
C.224
D.238
E.262

3.One quantity of rice priced at Rs 9.30 per Kg is mixed with another quality at a certain rate in the ratio 8:7. If the mixture so formed be worth Rs 10 per Kg, what is the rate per Kg of the second quality of wheat?
A.12.75
B.10.80
C.15.50
D.20.25
E.18.50

4.How many kgs of rice of variety-1 costing Rs.42/kg should a shopkeeper mix with 25 kgs of rice of variety-2 costing Rs.24 per kg so that he makes a profit of 25% on selling the mixture at Rs.40/kg?
A.15
B.20
C.25
D.30
E.None of these

5.An alloy contains Brass, Iron and Zinc in the ratio 2:3:1 and another contains Iron, zinc and lead in the ratio 5:4:3.If equal weights of both alloys are melted together to form a third alloy, then what will be the weight of lead per kg in new alloy?
A.5 1/9
B.1/4
C.4 1/7
D.1/8
E.2/7

6.A can contains 50 litres of milk. 10 litres of this milk is taken out and replaced with water. This process is repeated twice. Find the amount of remaining milk in the mixture?
A.127/3 litres
B.26 2/3 litres
C.87litres
D.128/5litres
E.27 2/3 litres

7.A milkman mixes 6 litres of free tap water with 20litres of pure milk. If the cost of pure milk is Rs.28 per litre the % Profit of the milkman when he sells all the mixture at the cost price is
A.25%
B.16.5%
C.30%
D.16(1/3)%
E.None of these

8.Rs 4000 is lent in 2 parts, 1 part at 8% per annum and 2nd part at 12% per annum. At the end of a year Rs 400 is received as simple interest. Find the part lent at 8% p.a.
A.3500
B.2500
C.2000
D.1500
E.1000

9.A 144 litres of mixture contains milk and water in the ratio 5 : 7. How much milk need to be added to this mixture so that the new ratio is 23 : 21 respectively?
A.36 litres
B.40 litres
C.28 litres
D.32 litres
E.30 litres

10.In a 100 litre mixture of milk and water, the % of water is only 20%. The milkman gave 25 litres of this mixture to a customer and then added 25 litres of water to the remaining mixture. What is the % of milk in the final mixture?
A.68%
B.57%
C.60%
D.53%
E.None of these

Explanation :
Suppose the vessel initially contains 9litres of liquid.
Let x litres of this liquid be replaced with water.
(4-(4x/9) +x) = (5-(5x/9))
X = 9/10
So, part of the mixture replaced = 9/10 * 1/9 = 1/10
Shortcut:
4:5—->9
1:1—->2
8:10
9:9
1/10

Explanation :
126*1+134*1+2x=177*4
260+2x=708
2x==708-260=448
x=448/2 = 224

Explanation :
Let the rate of second quality be Rs x per Kg.
9.30…..…………x
…………10………….
8………………………7
7X – 70 = 5.6
X = 10.80

Explanation :
25% profit by selling the mixture at Rs.40/kg, his cost per kg of the mixture = Rs.32/kg.
(x×42)+(25×24)=32(x+25)
42x+600=32x+800
10x=200
x=20kgs.
Shortcut:
125 = 40
100 = 32
42……………….24
………32…………..
8…………………….10
10 = 25
8 = 20

Explanation :
Shortcut:
In the first alloy,
2:3:1     =6*2
5:4:3 =12
Multiply 2 to make it equal,
4:6:2
5:4:3
4:11:6:3=24
3/24=1/8

Explanation :
Remaining milk = 50 [1 – (10/50)]3 = 128/5

Explanation :
Profit=28*6=728
Cp=28*20=560
Profit = 168*100/560=30%

Explanation :
Effective interest rate = 400/4000*100 = 10
8…………………12
……… 10………..
2…………………..2
1:1
1/2*4000 = 2000

Explanation :
144 == 5:7
60 : 84
Now == 21 = 84
23 = 92
92-60 = 32